首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1506427篇
  免费   142775篇
  国内免费   8590篇
耳鼻咽喉   21727篇
儿科学   48718篇
妇产科学   39489篇
基础医学   190613篇
口腔科学   38226篇
临床医学   148189篇
内科学   326615篇
皮肤病学   39331篇
神经病学   127231篇
特种医学   62287篇
外国民族医学   274篇
外科学   252586篇
综合类   32149篇
现状与发展   75篇
一般理论   444篇
预防医学   115640篇
眼科学   32116篇
药学   96681篇
  5篇
中国医学   2326篇
肿瘤学   83070篇
  2021年   12051篇
  2018年   20834篇
  2017年   17867篇
  2016年   20909篇
  2015年   22589篇
  2014年   35154篇
  2013年   45329篇
  2012年   43425篇
  2011年   46213篇
  2010年   35118篇
  2009年   37991篇
  2008年   43773篇
  2007年   44772篇
  2006年   48011篇
  2005年   44038篇
  2004年   41553篇
  2003年   39536篇
  2002年   37492篇
  2001年   69787篇
  2000年   70888篇
  1999年   59774篇
  1998年   20364篇
  1997年   18425篇
  1996年   19284篇
  1995年   19278篇
  1994年   17054篇
  1993年   15735篇
  1992年   48429篇
  1991年   47127篇
  1990年   45033篇
  1989年   42979篇
  1988年   39813篇
  1987年   38962篇
  1986年   36732篇
  1985年   35373篇
  1984年   26965篇
  1983年   22688篇
  1982年   14451篇
  1981年   12948篇
  1980年   12150篇
  1979年   23879篇
  1978年   17455篇
  1977年   14824篇
  1976年   13465篇
  1975年   14035篇
  1974年   16348篇
  1973年   15636篇
  1972年   14491篇
  1971年   13254篇
  1970年   12135篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
The aim of the present study was to explore differences in the clinical expression, clinical diagnoses and management of airway diseases in a primary-care setting. Patients aged >or=35 yrs who had ever smoked were enrolled when they presented for any reason to one of eight rural primary-care practices. Respiratory symptom questionnaires and spirometry were administered. In total, 1,034 patients had acceptable and reproducible spirometry, of whom 550 (53%) were males and 484 (47%) were females. Males smoked more than females (41.2 versus 29.2 pack-yrs) respectively, and were more likely to have a pre-bronchodilator forced expiratory volume in one second/forced vital capacity <0.70 at 22.4 versus 11.8%, respectively. However, more females than males reported breathlessness (51.0 versus 42.8%, respectively), a prior diagnosis compatible with airflow obstruction and taking respiratory medications (23.4 versus 14.9%, respectively). In conclusion, the current results suggest that females are more likely than males to report breathlessness and be prescribed respiratory medications independent of differences in the severity of airflow obstruction.  相似文献   
65.
66.
67.
68.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  相似文献   
69.
70.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号